It turns out I won't be able to keep my current tub, after all--my bro-in-law, V. (who's probably going to be doing the work since he has beaucoups experience with it) says it's too rusted and trying to fix it would cost more than just replacing it. So I'll be getting a new iron tub (I don't like the plastic ones--they don't feel stable underfoot; makes me feel like I'm living in a motel room).
Also, my personal designer (sister A.) reminded me that the tall, narrow linen cabinet I was thinking about would mess up our goal of visually widening the bathroom space, so I'll be getting a slightly wider vanity instead, one that has shelves behind doors (instead of drawers and a sort-of useable space under the sink). I didn't know they made 'em like that. The wider vanity means I can get a wider medicine cabinet and put light sconces on either side instead of a light over the top. Nice....
It also turns out that an over-the-john cabinet can be recessed into the wall just like a medicine cabinet (well, of course!), so I can have extra storage there, too, without cutting too deeply into the space. Any amount of storage we can shoehorn into this little room is a great thing!
I took pix of my bathroom as-is and put them up on my Flickr page, along with three plans I drew yesterday while taking measurements. Now to start collecting goodies so they'll all be ready for my remodeler. Of course, that'll take quite a while, because I also have some debt left to pay off over the next several months, but I'll do what I can when I can. Just have to dial down my eagerness a bit. :) "All good things to those who wait...."